16 December 2017
Int J Med Sci 2015; 12(12):968-973. doi:10.7150/ijms.13121
QT interval Independently Predicts Mortality and Heart Failure in Patients with ST-Elevation Myocardial Infarction
1. Division of Cardiology, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan;
Objectives: Heart-rate corrected QT (QTc) interval predicts cardiovascular mortality or all-cause mortality in the general population. Little is known about the best cut-off value of QTc interval for predicting clinical events in patients with ST-elevation myocardial infarction (STEMI).
Methods: We enrolled 264 patients with STEMI who received measurement of QTc intervals at ER (QTc-ER), on day 2 (QTc-D2), and on day 3 (QTc-D3) of hospitalization. Clinical events, including all-cause death and readmission for heart failure, were followed for 2 years.
Results: Prolonged QTc-ER, but not QTc-D2 or QTc-D3, well predicted clinical events with the best cut-off value of 445 ms. Patient with QTc-ER > 445 ms had lower left ventricular ejection fraction at baseline and at 6 months. Kaplan-Meier survival curves showed that the combination of QTc-ER > 445 ms and N-terminal pro-brain natriuretic peptide (NT-pro BNP) > 936 pg/mL was a strong predictor of clinical events (p<0.001). In multivariable Cox regression analysis, the independent predictors of death and heart failure were QTc-ER (p<0.001), log NT-proBNP (p<0.001), diabetes mellitus (p<0.001), history of stroke (p=0.001), and left ventricular end diastolic volume index (p<0.001).
Conclusion: QTc-ER > 445 ms independently predicts clinical events in STEMI, providing incremental prognostic value to established clinical predictors and NT-proBNP.
Keywords: QT interval, brain natriuretic peptide, acute myocardial infarction, left ventricular remodeling.
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How to cite this article:
Lin JF, Hsu SY, Wu S, Teng MS, Chou HH, Cheng ST, Wu TY, Ko YL. QT interval Independently Predicts Mortality and Heart Failure in Patients with ST-Elevation Myocardial Infarction. Int J Med Sci 2015; 12(12):968-973. doi:10.7150/ijms.13121. Available from http://www.medsci.org/v12p0968.htm